This invention pertains to an apparatus for use with fluorescent electrical lamp fixtures having sockets at two of its ends to extend the effective length of the sockets and permit the use of shorter lamps.
Standard ceiling lamp fixtures for use with fluorescent lamps are ordinarily modular in design and fit into standard ceiling troffer modular fixtures. Many such fixtures are designed to accept 4-foot long fluorescent lamps, typically operating at 40 watts each. These modular ceiling fixtures are as short as the 4-foot lamps they are designed to accept. Furthermore, such ceiling fixtures generally are shallow in order to fit into the ceilings and include a reflector spaced only a short distance from the lamp.
In order to replace light bulbs when one or more of the fluorescent lamps has failed, the lamps must be removed diagonally from the fixture due to the short length of the fixture. The metal reflector is also very close to the installed fluorescent lamps and makes installation and removal of the lamp even more difficult. The typical fluorescent lamp of the rapid start type has two bi-pin bases which mate with pairs of standard tombstone type sockets (one located at each end) making it necessary to twist the lamp to install it in or remove it from its pairs of sockets. Due to the closeness of the reflector it is often not possible to get hands or fingers around the bulb and it is therefore necessary to twist the bulb with the fingers only which may be difficult.
Furthermore, tombstone sockets tend to be fragile, usually being made of inexpensive plastic molding having spring contacts therein. During the removal or insertion of the lamps from the tombstone sockets, these sockets are easily damaged neccessitating the replacement of both the lamp and the socket. Maintenance costs for replacement of a lamp may therefore be unexpectedly high.
In addition, it is also difficult to install lamps in modular ceiling fixtures since, in order to insure proper alignment of the lamp pins, it is necessary to be able to see both ends of the lamp at the same time. This is difficult due to the length of the lamp. It is therefore necessary to insert the lamps by "feel" and this also leads to damage to the tombstone sockets.
One solution to this problem would be to use a shorter lamp bulb and a correspondingly shorter fixture in the existing ceiling fixtures. The existing ceiling fixtures, however, cannot accept shorter lamps since the pins of both ends of a fluorescent lamp must be firmly seated against the contacts in the tombstone sockets at either end of the lamp fixture. To use a shorter lamp in a standard 40 watt fixture, an adapter is necessary.
It is known that shorter fluorescent lamps utilize less wattage and produce less light output then a correspondingly longer lamp. Substitution of shorter lamps for the standard lamp will permit a corresponding decrease in energy usage. Where a decrease in lumens output can be tolerated, the energy savings afforded by a shorter lamp can be significant.